US4304818A - Insulation system for winding of electric rotating machines and process of production thereof - Google Patents

Insulation system for winding of electric rotating machines and process of production thereof Download PDF

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US4304818A
US4304818A US06/103,571 US10357179A US4304818A US 4304818 A US4304818 A US 4304818A US 10357179 A US10357179 A US 10357179A US 4304818 A US4304818 A US 4304818A
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polyisocyanate
polyepoxide
residue
winding
catalyst
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Hideyo Hirata
Takeshi Hakamada
Misao Souma
Masao Matsui
Yoshiyuki Suda
Yoshiharu Karasawa
Toshikazu Narahara
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Hitachi Ltd
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Hitachi Ltd
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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G18/00—Polymeric products of isocyanates or isothiocyanates
    • C08G18/003—Polymeric products of isocyanates or isothiocyanates with epoxy compounds having no active hydrogen
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G59/00—Polycondensates containing more than one epoxy group per molecule; Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups
    • C08G59/18—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
    • C08G59/40—Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing characterised by the curing agents used
    • C08G59/4007—Curing agents not provided for by the groups C08G59/42 - C08G59/66
    • C08G59/4014—Nitrogen containing compounds
    • C08G59/4028—Isocyanates; Thioisocyanates
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G73/00—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups C08G12/00 - C08G71/00
    • C08G73/06—Polycondensates having nitrogen-containing heterocyclic rings in the main chain of the macromolecule
    • C08G73/0622—Polycondensates containing six-membered rings, not condensed with other rings, with nitrogen atoms as the only ring hetero atoms
    • C08G73/0638—Polycondensates containing six-membered rings, not condensed with other rings, with nitrogen atoms as the only ring hetero atoms with at least three nitrogen atoms in the ring
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • H01B3/302—Polyurethanes or polythiourethanes; Polyurea or polythiourea
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • H01B3/303—Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups H01B3/38 or H01B3/302
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
    • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
    • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
    • H01B3/40—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes epoxy resins
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K3/00—Details of windings
    • H02K3/30—Windings characterised by the insulating material
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/2936—Wound or wrapped core or coating [i.e., spiral or helical]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
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    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
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    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/2964—Artificial fiber or filament
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    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/2964—Artificial fiber or filament
    • Y10T428/2967—Synthetic resin or polymer
    • Y10T428/2969—Polyamide, polyimide or polyester
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
    • Y10T428/2913—Rod, strand, filament or fiber
    • Y10T428/2933—Coated or with bond, impregnation or core
    • Y10T428/2971—Impregnation
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
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    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31511—Of epoxy ether
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/31547—Of polyisocyanurate
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/31551—Of polyamidoester [polyurethane, polyisocyanate, polycarbamate, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/31562—Next to polyamide [nylon, etc.]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y10T428/31598—Next to silicon-containing [silicone, cement, etc.] layer
    • Y10T428/31601—Quartz or glass
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
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    • Y10T428/31721—Of polyimide
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
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    • Y10T428/00—Stock material or miscellaneous articles
    • Y10T428/31504—Composite [nonstructural laminate]
    • Y10T428/31725—Of polyamide

Definitions

  • the present invention relates to an insulation system for winding of electric rotating machines and a process for the production of such an insulated winding for electric rotating machines. More particularly, the invention pertains to an insulated winding for electric rotating machines having thermal resistance of class H or more obtained by impregnating and curing a novel thermosetting resin and a process for the production of such an insulated winding for electric rotating machines.
  • a tape or sheet of a polyimide, polyamideimide, aromatic polyamide or the like resin has heretofore been used as an insulating material having thermal resistance of class H (180° C.) for winding for such electric rotating machines.
  • a polyimide resin varnish or a polyamideimide resin varnish is known as an insulating varnish of class H for impregnating insulating material but they are difficult to be a solventless varnish since they are condensation resin varnishes. Therefore, they are not suitable for winding for electric rotating machines in which the formation of voids is undesirable.
  • an epoxy resin varnish As a solventless varnish for impregnating insulating materials, an epoxy resin varnish has been widely used, but the epoxy resin has thermal resistance of class F (155° C.). When the resin is heated at a temperature of 180° C. or more, therefore, delamination occurs owing to heat deterioration between the insulating layers of the winding and particularly between the conductor and the insulating layer. Thereby thermal conduction is reduced and the temperature of the winding further increases. Also, corona starting voltage is reduced and dielectric breakdown is brought about.
  • said insulating layer is easy to peel from the conductor if the adhesive property of the varnish forming the insulating layer is poor. Since the machines are not immersed in an oil like a transformer, a corona is generated and dielectric breakdown occurs.
  • a silicone resin varnish is known as another varnish having excellent thermal resistance, but it is inferior in adhesiveness and is not suitable for such electric rotating machines.
  • An object of the present invention is to provide insulation system for winding of electric rotating machines having thermal resistance of class H or more.
  • Another object of the invention is to provide insulated winding for electric rotating machines having excellent adhesiveness between a conductor and an insulating layer.
  • a further object of the invention is to provide insulated windings for electric rotating machines having resistance to thermal stress.
  • FIG. 1 shows a change of the breakdown voltage of a model bar coil after deterioration test.
  • FIG. 2 is a plan of a field coil for a direct current motor.
  • FIG. 3 shows the schedule of heat cycles in class H heat cycle test.
  • FIG. 4 is a rough sketch of an armature coil for a direct current motor.
  • FIG. 5 shows a relationship between dielectric loss tangent and temperature in the insulating layer of a model coil.
  • FIGS. 6a-6f are infrared spectra showing structures of a resin in the course of the production thereof.
  • insulated winding for electric rotating machines can be produced by wrapping a plurality of layers of a sheet-form insulating material of glass fibers, a polyimide, polyamideimide or aromatic polyamide around a winding conductor for electric rotating machines, impregnating the layers with a solventless varnish comprising a polyepoxide, an organic polyisocyanate, and then curing the varnish in the presence of a catalyst for forming isocyanurate rings and oxazolidone rings.
  • thermosetting resin The detailed composition, preparation and properties of the above-mentioned thermosetting resin are described in U.S. Patent Application Ser. No. 418,905, filed Nov. 26, 1973, now abandoned.
  • the term "electric rotating machines” used herein means generators and motors having an allowable temperature of 180° C. or more.
  • a polyimide KAPTON® manufactured by E. I. du Pont de Nemours & Co. in U.S.A.
  • an aromatic polyamide NOMEX® manufactured by E. I. du Pont de Nemours & Co. in U.S.A.
  • a polyamideimide PAIFRON® manufactured by Hitachi Chemical Co., Ltd. in Japan
  • another class H insulating material such as a glass cloth tape or a mica tape may be used if necessary.
  • thermosetting resin having recurring units of at least two isocyanurate rings directly bonded to one another through residue of the polyisocyanate and two oxazolidone rings directly bonded to each other through residue of the polyepoxide represented by the formula (I), ##STR1## wherein R is a residue of the polyisocyanate, R' is a residue of the polyepoxide, p is an integer of at least 2, and m and r are integers of at least 1.
  • the feature of the oxazolidone-modified isocyanurate polymers in the U.S. Patent is in that one isocyanurate ring is inserted between one group of oxazolidone rings and the other group of oxazolidone rings. This is an outstanding point to distinguish the cured varnish used in the present invention from the polymers disclosed in the U.S. Patent.
  • the cured varnish used in the present invention there are at least two isocyanurate rings directly connected to each other through a residue of an organic polyisocyanate. By virtue of the difference in their chemical structure, they show different properties shown below.
  • compositions shown in Tables 2 and 3 were cured under a condition of 80° C./5 hours plus 150° C./15 hours, respectively.
  • Test pieces were prepared from the cured products obtained as above and subjected to the determination of tensile strength, elongation and thermal deterioration in accordance with the same manner as shown in the specification of U.S. Patent Application Ser. No. 418,905, respectively. The results obtained are as shown in Table 4.
  • Infrared spectrum analysis of the chemical structure of the resins used in the present invention shows that trimerization of a polyisocyanate takes place at first in the presence of a catalyst for forming isocyanurate rings and oxazolidone rings and then the reaction between the polymer of polyisocyanate and a polyepoxide takes place to form oxazolidone rings. Since the equivalent ratio of the polyisocyanate to the polyepoxide is more than one and the trimerization reaction precedes the oxazolidone forming reaction, at least two isocyanurate rings are directly connected to each other through one residual group of the polyisocyanate.
  • FIGS. 6a to 6f are infrared spectra showing the reaction mechanism.
  • FIGS. 6a to 6f it is apparent that at first the sample exhibits the charactersitics due to isocyanate and epoxy groups (FIG. 6a) and then the characteristics due to isocyanurate and epoxy groups (FIG. 6b). With the progress of the reaction, characteristics due to oxazolidone rings are observed (FIGS. 6c to 6f) at 1760 cm -1 . The longer the reaction time, the stronger the absorption due to oxazolidone rings becomes and the weaker the absorption due to epoxy rings becomes.
  • sample used in analysis at zero time was diluted two times thinner than the other samples, so as to show the full absorption peak due to isocyanate groups.
  • thermosetting resin are superior as winding insulation for electric rotating machines to the winding insulated with a prior art epoxy resin since the thermosetting resin used in the present invention shows good adhesiveness for a conductor such as copper or aluminum.
  • more than one equivalent of an organic polyisocyanate is blended with 1 equivalent of a polyfunctional epoxy compound.
  • An amount of the polyepoxide is such that oxazolidone rings are introduced in the cured resins. From the view point of mechanical properties of the cured resin, more than 2 equivalents of the polyisocyanate per one equivalent of the polyepoxide is used. When the amount of polyisocyanate exceeds 15, there is a tendency that the cured resin becomes hard. The thus obtained hard resin can be used as it is in cases wherein flexibility is not required.
  • the curing is carried out by heating at a temperature of 130° C. or less and preferably above about 60° C., for 5-15 hours and then heating at a temperature of 150° C. or more for 5-15 hours.
  • isocyanurate rings are formed mainly by the trimerization of the polyisocyanate.
  • oxazolidone rings are formed and cross-linking and curing occur.
  • an insulating varnish which yields a thermosetting resin by heating is used, said tape or sheet insulating material and the winding conductor are tightly bonded so that delamination may not occur even at high temperatures.
  • the polyfunctional epoxides or polyepoxides used in the present invention have at least two vicinal epoxy groups or 1,2-epoxy groups in the molecule.
  • bifunctional epoxides such as, for example, diglycidylether of bisphenol A, butadiene diepoxide, 3,4-epoxycyclohexylmethyl-(3,4-epoxy)-cyclohexane carboxylate, vinylcyclohexene dioxide, 4,4'-di(1,2-epoxyethyl)diphenylether, 4,4'-di(1,2-epoxyethyl)biphenyl, 2,2-bis(3,4-epoxycyclohexyl)propane, diglycidylether of resorcinol, diglycidylether of phloroglucinol, diglycidylether of methylphloroglucinol, bis-(2,3-epoxycyclopentyl)
  • diglycidylether of bisphenol A and polyglycidylether of phenol-formaldehyde novolac have a particular good reactivity. Therefore, they are useful compounds. Further, halides of these compounds can be used, too.
  • diepoxides are employed.
  • organic polyfunctional isocyanates or polyisocyanates there can be used bifunctional isocyanates, such as, for example, methane diisocyanate, butane-1,1-diisocyanate, ethane-1,2-diisocyanate, butane-1,2-diisocyanate, transvinylene diisocyanate, propane-1,3-diisocyanate, butane-1,4-diisocyanate, 2-butene-1,4-diisocyanate, 2-methylbutane-1,4-diisocyanate, pentane-1,5-diisocyanate, 2,2-dimethylpentane-1,5-diisocyanate, hexane-1,6-diisocyanate, heptane-1,7-diisocyanate, octane-1,8-diisocyanate, nonane-1,9-diisocyanate, decane-1,10
  • compounds obtained by masking isocyanic radicals of the aforesaid isocyanates with phenol, cresol and the like can be used, too.
  • the dimers and trimers of these isocyanates are usable, too.
  • 4,4'-diphenylmethane diisocyanate, 2,4-toluene diisocyanate are preferable and useful.
  • the aforesaid epoxides and isocyanates are each used solely or in combination with one another. In order to obtain a low viscosity varnish, diisocyanates are particularly useful.
  • a catalyst displays an important role for obtaining the heat resistant insulating system of the present invention.
  • the catalyst is used to form isocyanurate bonds and oxazolidone bonds at the time of curing.
  • Such a catalyst as above includes morpholine derivatives, such as, for example, N-dodecylmorpholine, butylene dimorpholine, hexamethylene dimorpholine, cyanoethyl morpholine, triazinoethyl morpholine, N-methyl morpholine, N-ethyl morpholine and the like.
  • imidazole derivatives as a catalyst, such as, for example, 2-methylimidazole, 2-ethylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-methyl-4-ethylimidazole, 1-butylimidazole, 1-propyl-2-methylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-phenylimidazole, 2,4-diamino-6-(2'-methylimidazolyl-1'-)-ethyl-s-triazine, 2,4-diamino-6-(2'-ethylimidazolyl-1'-)-ethyl-s-triazine, 2,4-diamino-6-(2'-undecylim
  • heterocycle forming catalysts are used within a range of 0.01 to 10% by weight, preferably 0.1 to 2% by weight, based on a mixture of said polyfunctional epoxide and polyfunctional isocyanate.
  • a method for impregnating a winding wrapped with said tape or sheet with a blend of said resin formulation comprising a polyfunctional epoxy compound and a polyfunctional isocyanate compound a method which comprises previously impregnating only the catalyst dissolved in an organic solvent and then impregnating the resin component is preferable.
  • the catalyst has no adverse effect on the pot life of the resin varnish in a storage tank and there is no fear of gelation of the varnish in the tank at room temperature.
  • the above-mentioned method of impregnating windings with the varnish is carried out under reduced pressure.
  • the viscosity of the impregnating varnish is preferably 7 poises or less, and more preferably 2 poises or less, at the impregnation temperature. If the viscosity exceeds 7 poises, it is feared that sufficient impregnation cannot be effected.
  • An aromatic polyamide (NOMEX) tape having a thickness of 0.075 mm was wound around a bar-form conductor having a section of 7.4 ⁇ 14.4 mm and a length of 550 mm, obtained by piling six flat type copper wires, four times at half lap to wrap the bar-form conductor. Further, a glass cloth tape having a thickness of 0.18 mm was wound around it one time at half lap to prepare a model winding.
  • NOMEX aromatic polyamide
  • the model winding was immersed in a 1% solution of 2-ethyl-4-methylimidazole, which is a catalyst forming isocyanurate rings and oxazolidone rings, in methanol to impregnate said solution, air-dried at room temperature, and dried at 40° C. and 0.1 mmHg for 5 hours.
  • a resin component consisting of 1 equivalent of diepoxide DER-332 (a bisphenol A epoxy resin manufactured by Dow Chemical Co. in U.S.A., epoxy equivalent 178) and 2 equivalents of diisocyanate MDI (4,4'-diphenylmethane diisocyanate) was then introduced under reduced pressure. The impregnation was carried out at 40° C. and 3 mmHg.
  • BDV breakdown voltage
  • the model winding according to the present invention (1) is smaller in the reduction of BDV and higher in thermal resistance than the model winding according to the prior art process (2).
  • a model coil having a shape similar to that of the field coil for a direct current motor as shown in FIG. 2 was prepared.
  • a NOMEX tape having a thickness of 0.075 mm was wound four times at half lap.
  • a glass cloth tape having a thickness of 0.18 mm was wound one time at half lap.
  • the size of the coil including the insulating layer was 105 mm ⁇ 300 mm ⁇ 60 mm and the sectional size of the conductor was 36 mm ⁇ 58 mm.
  • the delamination between the conductor and the insulating layer was judged by striking the surface of the insulating layer with a small hammer and hearing the sound. This method permitted easy and correct judgement without requiring any particular skill.
  • a prior art epoxy resin varnish was applied to an armature coil for a direct current motor as shown in FIG. 4.
  • slot length was about 600 mm or more, it was impossible to subject the coil and an iron core to integral impregnation since the coil insulating layer broke down owing to the stress produced by a difference in thermal expansion caused by heat cycles between the coil insulating layer and the iron core.
  • a model bar coil having a length of about 1,000 mm was prepared and insulated in the same manner as in Example 1.
  • the insulated model bar coil was inserted into a slot having a width of 20 mm, a depth of 36 mm and a length of 850 mm and then impregnated with the resin varnish of Example 1 to prepare an armature model.
  • the impregnation and curing conditions were the same as in Example 1 except that the catalyst was directly added to the resin component in an amount of 1% by weight.
  • the armature model For the armature model, 500 heat cycles of 60° C. ⁇ 180° C. were carried out, heating at 220° C. for 10 days was effected, and then 500 heat cycles of 60° C. ⁇ 180° C. were again carried out, and its BDV was measured. As a result, the armature model according to the present invention showed only a slight reduction in BDV but were all right. On the other hand, breakdown occurred in the case of armature model prepared with the prior art cycloaliphatic epoxy resin-acid anydride curing system varnish.
  • the insulated winding for electric rotating machines according to the present invention has excellent thermal resistance and adhesiveness which have not been obtained, and can be used as an insulated winding having thermal resistance of class H or class C.
  • the pot life of the impregnating varnish used in the present invention is short when a catalyst which forms isocyanurate rings and oxazolidone rings is added. Therefore, it is desirable to previously impregnate layers of the tape or sheet wound around a conductor with this catalyst alone.
  • the impregnation is carried out by dissolving a required amount of the catalyst in an organic solvent.
  • part of the epoxy resin may be used as a binder.
  • the solvent methanol, acetone, toluene, benzene, ethyl alcohol, methyl ethyl ketone, dimethylformamide, etc. may be used.
  • the amount of the catalyst used is 0.1-2% by weight based on the weight of the resin to be impregnated, the amount of the binder used is 10-400% by weight based on the weight of the catalyst and the amount of the solvent used is 10-100 times the weight of the catalyst.
  • This example illustrates an insulation for low voltage electric machines consisting mainly of a polyamide film.
  • a glass cloth tape and a polyamide (NOMEX) non-woven fabric tape were wound around a conductor a prescribed number of times. Then, 15 g of 2-phenylimidazole as a catalyst for the resin and 35 g of a novolac epoxy resin having a melting point of about 70° C. as a binder were mixed with 1 l of acetone to prepare a solution. Said winding was immersed in this catalyst treating solution for 30 minutes. After the immersion, the treated winding was dried at room temperature under reduced pressure, impregnated with a varnish obtained by mixing 1 equivalents of a bisphenol A epoxy compound with 2.5 equivalents of 4,4'-diphenylmethane diisocyanate, and then cured by heating. Thus, an insulated winding having very high thermal resistance was obtained.
  • the catalyst penetrated into each layer of the insulation completely and was stuck to each layer uniformly.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Polymers & Plastics (AREA)
  • Health & Medical Sciences (AREA)
  • Medicinal Chemistry (AREA)
  • Organic Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Power Engineering (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacture Of Motors, Generators (AREA)
  • Polyurethanes Or Polyureas (AREA)
  • Insulation, Fastening Of Motor, Generator Windings (AREA)
  • Epoxy Resins (AREA)
  • Organic Insulating Materials (AREA)
US06/103,571 1973-09-19 1979-12-14 Insulation system for winding of electric rotating machines and process of production thereof Expired - Lifetime US4304818A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP48104993A JPS5058501A (ja) 1973-09-19 1973-09-19
JP48/104993 1973-09-19

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US05506337 Continuation-In-Part 1974-09-16

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US (1) US4304818A (ja)
JP (1) JPS5058501A (ja)
AU (1) AU477108B2 (ja)
CA (1) CA1021245A (ja)
DE (1) DE2444458C3 (ja)
ES (1) ES430175A1 (ja)
FR (1) FR2244285B1 (ja)
GB (1) GB1462200A (ja)
ZA (1) ZA745933B (ja)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4376904A (en) * 1981-07-16 1983-03-15 General Electric Company Insulated electromagnetic coil
US4399190A (en) * 1981-03-11 1983-08-16 Mitsubishi Denki Kabushiki Kaisha Thin insulating mica sheet and insulated coil
US4399191A (en) * 1981-03-11 1983-08-16 Mitsubishi Denki Kabushiki Kaisha Thin insulating mica sheet and insulated coil
US4400226A (en) * 1981-07-16 1983-08-23 General Electric Company Method of making an insulated electromagnetic coil
US5084544A (en) * 1989-02-11 1992-01-28 Bayer Aktiengesellschaft Cold setting reaction resin mixture and use thereof
WO2002073772A1 (en) * 2001-03-14 2002-09-19 Akzo Nobel N.V. Powder coated rotor
US20020187351A1 (en) * 2001-03-14 2002-12-12 Borschel Volker Karl Ottmar Powder coated rotor
US20040265167A1 (en) * 2003-06-30 2004-12-30 Todd Morrison Sterilization vacuum chamber door closure
CN102148069A (zh) * 2009-12-23 2011-08-10 通用汽车环球科技运作有限责任公司 用于磁导线的自我修复的绝缘体
CN102148069B (zh) * 2009-12-23 2016-11-30 通用汽车环球科技运作有限责任公司 用于磁导线的自我修复的绝缘体

Families Citing this family (8)

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JPS53116402A (en) * 1977-03-19 1978-10-11 Hitachi Ltd Electric insulation device
JPS54157201A (en) * 1978-06-02 1979-12-12 Hitachi Ltd Wire manufacturing method for electric machine
JPS6055971B2 (ja) * 1978-12-08 1985-12-07 株式会社日立製作所 電機巻線
EP0035072B1 (de) * 1980-03-03 1984-06-13 BBC Aktiengesellschaft Brown, Boveri & Cie. Duroplastisch härtbare lösungsmittelfreie Harzmischung und ihre Verwendung
JPS56150813A (en) * 1980-04-22 1981-11-21 Mitsubishi Electric Corp Manufacture of insulated coil
FR2507024A1 (fr) * 1981-06-01 1982-12-03 Hitachi Ltd Procede de production de bobinages electriques isoles
DE3323122A1 (de) * 1983-06-27 1985-05-23 Siemens AG, 1000 Berlin und 8000 München Verfahren zur herstellung von reaktionsharzformstoffen
DE3323154A1 (de) * 1983-06-27 1985-01-03 Siemens AG, 1000 Berlin und 8000 München Verfahren zur impraegnierung und einbettung von elektrischen wicklungen

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US3793236A (en) * 1971-02-12 1974-02-19 Mitsubishi Chem Ind Oxazolidone-modified isocyanurate resins

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BE593093A (ja) * 1959-09-12
BE613493A (ja) * 1961-02-06 1900-01-01
DE1258937B (de) * 1961-03-11 1968-01-18 Asea Ab Glimmerband zur Herstellung eines elektrischen Leiters
US3211703A (en) * 1962-03-23 1965-10-12 Monsanto Res Corp Polyaliphatic polyisocyanurate laminating resin prepared in the presence of a cocatalyst system
US3206352A (en) * 1962-03-23 1965-09-14 Monsanto Res Corp Polymeric polyisocyanurate laminating resin prepared from a diaryl dhsocyanate and acocatalyst system
DE1219554B (de) * 1963-03-08 1966-06-23 Siemens Ag Verfahren zur Herstellung von Isolierungen aus Folien oder Baendern mit Kunstharztraenkung
DE1490393B1 (de) * 1963-04-11 1970-07-02 Siemens Ag Verfahren zur Herstellung von Isolierungen fuer elektrische Maschinen,Geraete oder Apparate
GB1050679A (ja) * 1963-05-02 1900-01-01
NL6504681A (ja) * 1965-04-13 1965-06-25
US3494888A (en) * 1966-08-30 1970-02-10 Wilbur R Mcelroy Resin compositions from polyepoxides and isocyanate polymers
US3745133A (en) * 1968-02-05 1973-07-10 Upjohn Co Cellular isocyanurate containing polymers
FR1566468A (ja) * 1968-03-04 1969-05-09

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US3793236A (en) * 1971-02-12 1974-02-19 Mitsubishi Chem Ind Oxazolidone-modified isocyanurate resins

Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4399190A (en) * 1981-03-11 1983-08-16 Mitsubishi Denki Kabushiki Kaisha Thin insulating mica sheet and insulated coil
US4399191A (en) * 1981-03-11 1983-08-16 Mitsubishi Denki Kabushiki Kaisha Thin insulating mica sheet and insulated coil
US4376904A (en) * 1981-07-16 1983-03-15 General Electric Company Insulated electromagnetic coil
US4400226A (en) * 1981-07-16 1983-08-23 General Electric Company Method of making an insulated electromagnetic coil
US5084544A (en) * 1989-02-11 1992-01-28 Bayer Aktiengesellschaft Cold setting reaction resin mixture and use thereof
WO2002073772A1 (en) * 2001-03-14 2002-09-19 Akzo Nobel N.V. Powder coated rotor
US20020187351A1 (en) * 2001-03-14 2002-12-12 Borschel Volker Karl Ottmar Powder coated rotor
US20040142189A1 (en) * 2001-03-14 2004-07-22 Volker Karl Ottmar Borschel Powder coated rotor
US20040265167A1 (en) * 2003-06-30 2004-12-30 Todd Morrison Sterilization vacuum chamber door closure
CN102148069A (zh) * 2009-12-23 2011-08-10 通用汽车环球科技运作有限责任公司 用于磁导线的自我修复的绝缘体
CN102148069B (zh) * 2009-12-23 2016-11-30 通用汽车环球科技运作有限责任公司 用于磁导线的自我修复的绝缘体

Also Published As

Publication number Publication date
ES430175A1 (es) 1977-01-16
ZA745933B (en) 1975-10-29
GB1462200A (en) 1977-01-19
DE2444458A1 (de) 1975-04-24
AU7346374A (en) 1976-03-25
JPS5058501A (ja) 1975-05-21
CA1021245A (en) 1977-11-22
FR2244285A1 (ja) 1975-04-11
DE2444458B2 (de) 1978-03-02
FR2244285B1 (ja) 1977-07-08
DE2444458C3 (de) 1985-06-20
AU477108B2 (en) 1976-10-14

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